Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

Schedule of minimum future commitments related to purchase obligations

The following table shows our minimum future commitments related to these purchase obligations as of December 31, 2016, including those of our subsidiaries.



				Payments Due By Period
(in millions)	Date Contracts Extend Through	Total Amounts Committed		2017		2018		2019		2020		2021		Later Years
Electric utility:
Nuclear	2033	$	9,599.8	$	415.3	$	420.1	$	445.4	$	475.1	$	501.1	$	7,342.8
Purchased power	2027	693.3		111.3		75.9		66.2		66.3		63.9		309.7
Coal supply and transportation	2019	455.0		269.4		140.3		45.3		—		—		—
Natural gas utility supply and transportation	2028	1,229.4		341.7		285.5		237.5		159.7		78.6		126.4
Total		$	11,977.5	$	1,137.7	$	921.8	$	794.4	$	701.1	$	643.6	$	7,778.9

Schedule of minimum future payments under noncancelable operating leases

Future minimum payments under noncancelable operating leases are payable as follows:



Year Ending December 31	Payments (in millions)
2017	$	9.9
2018	8.8
2019	5.9
2020	5.3
2021	5.5
Later years	60.1
Total	$	95.5

Schedule of regulatory assets and reserves related to manufactured gas plants

We have established the following regulatory assets and reserves related to manufactured gas plant sites as of December 31:



(in millions)	2016		2015
Regulatory assets	$	702.7	$	697.0
Reserves for future remediation	633.4		628.0

- Definition

Tabular disclosure of a lessee's leasing arrangements including: (1) the basis on which contingent rental payments are determined, (2) the existence and terms of renewal or purchase options and escalation clauses, (3) restrictions imposed by lease arrangements, such as those concerning dividends, additional debt, and further leasing, (4) rent holidays, rent concessions, or leasehold improvement incentives and unusual provisions or conditions. Disclosure may also include the specific period used to amortize material leasehold improvements made at the inception of the lease or during the lease term. Additionally, for operating leases having initial or remaining noncancelable lease terms in excess of one year: (a) future minimum rental payments required as of the date of the latest balance sheet presented, in the aggregate and for each of the five succeeding fiscal years, (b) the total of minimum rentals to be received in the future under noncancelable subleases as of the date of the latest balance sheet presented, and (c) for all operating leases, rental expense for each period for which an income statement is presented, with separate amounts for minimum rentals, contingent rentals, and sublease rentals. Rental payments under leases with terms of a month or less that were not renewed need not be included.

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